It is found that the conventional exercise bicycle which is constructed in the manner of a stationary bicycle with foot pedals, a chain drive system and a flywheel. However, such exercise bicycle is complex in structure and fails to provide a means for adjusting the force required to overcome the resistance in operation.
Therefore, it is an object of the present invention to provide an adjustable roller structure for an exercising stationary bicycle which may obviate and mitigate the above-mentioned drawbacks.